Intraoperative sonography of a spinal cord arteriovenous malformation.

Spinal cord arteriovenous malformations (A VMs), although comparatively rare , are important because of their potential to be cured surgically. Yet they are often undiagnosed preoperatively because of their protean natural history [1). Preoperative myelography and/or CT scanning may demonstrate only a mass without other clues to the vascular nature of the lesion , thus not prompting a definitive spinal angiogram. Intraoperative sonography provides a means to evaluate the spinal cord and subarachnoid space before incising the dura mater and performing a potentially dangerous myelotomy or exploratory cord retraction. We report a case of an unsuspected spinal AVM in which intraoperative sonography played a significant diagnostic role .